The Efficacy of the KARL STORZ Curved Fetoscope and Straight Fetoscope for Laser Photocoagulation of Placental Anastomoses

Inclusion Criteria: * pregnancy * The patient fulfills the criteria for laser photocoagulation of placental anastomoses based on the standard of care * fetal diagnosis of twin-to-twin transfusion syndrome * Anterior placenta * The patient provides signed informed consent that details the maternal and fetal risks involved with the procedure Exclusion Criteria: * Contraindication to abdominal surgery, fetoscopic surgery, or general anesthesia * Allergy or previous adverse reaction to a study medication specified in this protocol * The patient does not fulfill the conventional criteria to undergo in-utero surgery, which is specific for each surgery * Preterm labor, preeclampsia, or a uterine anomaly (e.g., large fibroid tumor) that is unavoidable during surgery in the index pregnancy * Fetal aneuploidy, genomic variants of known significance if an amniocentesis has been performed, other major fetal anomalies or disorders that may impact the fetal/neonatal survival, or a known syndromic mutation * Suspicion of a major recognized syndrome by ultrasound or MRI * Maternal BMI \>40 kg/m2 * High risk for fetal hemophilia